Door opening means



OcL 29, l1940. R. l. scHCNlTzER DOOR OPENING MEANS Filed Feb'. 5, y1940 2 sheets-sneer 1 INVENTOR.

RUDOLPH I. SCHONITZER.

A A RNEYS.

Oct. 29, 1940.

R. l. SCHONITZER Doon OPENING MEANS .l Filed Feb. 5, 1940 2 sheets-sneer 2 l lllilllllul: in lill. :llllllnh BY r '- A oRNEYs FIG.6

Patented Oct. 29, 19,40

UNITED STATES `Pliulazlv OFFICE noon OPENING, MEANS' l f Rudolph r. schwarzer, snake:- neigut, omo Application February 5, 1940, Serial No. 317,299

6 Claims.

open position (said door being manually movable 6 to its fully open position if the position to which said door is automatically movable is a partially open position thereof), and for yieldingly resisting, but only to a desirable degree, the closing of said door from the predetermined open position to which it is automatically-movable. More particularly, the present invention relates to means for automatically opening, and for yieldingly resisting the closing of, a door which is so hinged on its supporting structure that the hinge edge wall of said door and the hinge edge wall of its supporting structurel are in oppositely positioned or generally abutting relationship when said door is in its closed position, suchas an automobile door, for example.

In order to automatically open a present-day automobile door (the average weight of which is about sixty-five pounds), by the use of means g in the region of its hinge edge wall (and hence within one or two inches of its hinge axis). a

relatively great force is required. This is particularly true (a) if the hinge axis of said door is so inclined (as it usually is) that said door has a normal tendency to close, and (b) if said door is mounted on the automobile body by concealed 3 hinges (as it usually is), inasmuch as the use of concealed hinges results, as will hereinafter more fully appear, in particularly unfavorableleverage conditions.

s One of the objects of the present invention.

for automatically opening, in a particularly effective and practical manner, a present-day'automobile door, even if the hinge axis of said door is so inclined that said door has a normal tendency to close, the'reciprocable plunger of said means being effective, as will hereinafter more fully appear, on said door or on that portion of the automobile body on which said door is hinged, in the region of the hinge edge wall of said door or body portion.

A further object of the present invention is the provision of plunger type means for automatically opening. in an especially effective and practical manner, a present-day automobile door which is mounted on an automobile lbody by concealed hinges, the use of such hinges resulting in particularly unfavorable leverage ,conditions, as heretofore DOinted out.

More specifically, it is an object of this invention to-provide door opening means which therefore, is the provision of plunger type means (Cif v1li-85) I comprises a reciprocable plunger carried by either the door structure to be automatically opened or the supporting structure therefor, said plunger having cooperative engagement with a bearing portion of the other structure (a por- 5 tion located in the region of the hinge edge wall thereof) for the purpose of automatically moving said door structure. upon the unlatching thereof, to a predetermined open position, and for the purpose of yieldingly resisting the closing of said door structure from the predetermined open position to which it is automatically movable.

, As will' hereinafter more fully appear, indoor opening means embodying the present invention, either the path of reciprocation of the plunger relative to the bearing portion with which it has cooperative engagement for door opening and door retaining purposes, or the disposition of said bearing portion relative to the path of reciprocation of said plunger, is such that when the `door with which such means is used is substantially mid-way between its closed position and the predetermined open position to which it is automatically movable, the path of reciprocation of said plunger and said bearing portion are sub-- stantially normal to each other. In other words, said bearing portion may be substantially normal to one or both of the side walls of said door. (or to the general plane of said door) and the path of reciprocation of said plunger may be such as to effect the aforesaid result, (the advantages of which hereinafter will be specifically referred to). as in that embodiment of the invention illustrated in Fig. 7, or the path of reciprocation of said plunger 'may be generally parallel with one or both of the side walls of said door (or with the general plane of said door) and said bearing portion may be so inclined as to bring about the aforesaid result, as in those embodiments of the invention illustrated in Figs. 1 to 5 inclusive.

If the plunger of door opening means embodying the present invention has cooperative engagement with an inclined bearing portion, for door opening and door retaining purposes, said bearing portion may bean inclined part ofV a bracket or the like suitably secured to the door to be opened or to its supporting structure (such as to the hinge edge wall thereof), as in that embodiment of the invention illustrated in Figs. l to 4 inclusive, or said bearing portion may be a simple depression in the hinge edge wall of said door or its supporting structure, as in that embodiment of the' invention illustrated in'Fig. 5. Furthermore, said plunger may be provided, if l5 desired and as shown in that embodiment of the invention illustrated in Fig. 5, with -a roller or the like for desirable rolling engagement with its cooperating bearing portion, all as will hereinafter more fully appear.

Another feature of each of the door opening means here illustrated is that the plunger thereof is a part of a self-contained plunger unit, which may be easily and conveniently secured to either the door or its supporting structure.

Other features of the here illustrated door opening means are their structural simplicity; their strong and rugged character, which enables them to have an exceedingly long life in service, without requiring attention from time to time; and the efficiency with which they perform their door opening function and their functionl of yieldingly resisting the closing of the doors with which they are used from the predetermined open positions to which said doors are automatically movable.

Further features of door opening means embodying the present invention are in part obviousand inpart will appear from the following description of three such means, reference being had to the accompanying drawings, in which Fig. 1 is an outside elevation of a portion of a left front automobile door and an adjacent portion of the automobile body on which said door is hinged, parts of the outer side walls of said door and body portions being broken away to expose theA door opening means associated therewith, said door being in its closed position; Fig. 2 is a horizontal sectional view, on an enlarged scale, through said door and body portions, on the line 2 2, Figs. 1 and 3, and the predetermined open position to which said door is automatically movable being indicated in dotted lines; Fig. 3 is an outside elevation,.as viewed from the line 3 3, Fig. 2, of said door and body portions, with parts of the outer side walls thereof broken away to expose said door opening means; Fig. 4 is a vertical sectional view through said body portion, on the line 4 4, Fig. 2; Fig. 5 is a view corresponding to'Flg. 2 but showing a modified form of door opening means embodying the present invention; Fig. 6 is a vertical sectional view through the door and body portions of Fig. 5, the view being on the line 6 6, Fig. 5; and Fig. 7 is a view corresponding to Figs. 2 and 5 but showing still another form of door opening means embodying the present invention.

Before the present invention is described in detail, it is to be understood that such invention is not limited to the details of construction or the specific arrangement of parts herein illustrated or described, as the invention obviously may take other forms. It also is to be understood that the phraseology or terminology herein employed is for the purposeof description and not of limitation.

Although each of the here illustrated door opening means is applicable for use with any .hinged door having its hinge edge wall oppositely positioned or in generally abutting relationship with respect to the hinge edge wall of its supportingstructure (the structure on which said door is hinged) each of said door opening means is particularly useful, as heretofore pointed out and as will hereinafter more fully appear, with the door of an automobile or the like, and for purposes of illustration and not of limitation, the use of three such door opening means with present-day automobile doors is here shown and described.

Referring first to Figs. 1 to 4 inclusive, the

reference numeral I designates a portion of a left front automobile door, said door having its transverse front edge wall 2 suitably hinged, as is usual, on the transverse rear edge wall 3 of that portion of the automobile body here shown and designated generally by the reference numeral 4.

Although said door may be hinged on said body portion` by the use of exposed hinges, or

by the use of one exposed hinge and one concealed hinge, a pair of concealed hinges are4 here utilized for that purpose, the hinge axis x-y of said door being so inclined, as indicated in 4, that said door, like most presenteither in actual contact or, as here shown, relal tively close to each other.

Although any suitable means may be utilized for releasably retaining the door I -in its closed position and for actuating said retaining means to release said door for opening movement, (said retaining means being hereinafter referred to broadly as latch means). door openingmeans embodying the present invention are particularly useful in conjunction with doors whose latch means have push-buttonsor the like for effecting release actuation thereof, as said door opening means automatically effect the opening of said doors upon the unlatching thereof. Projecting door handles, by the use of which present-day automobile doors are unlatched and manually opened, not only are dangerous (in that many severe im'uries have been caused by them) but also, said projecting handles seriously interfere with the streamlining effects now desired for automobile bodies. Inasmuch as each door opening means embodying the present invention automatically effects, upon the unlatching of the door with which it is used, the opening of said door, the use for such door of the present-day handles for door opening purposes is wholly unnecessary. As a result, simple pushbuttons or the like, desirable from many-standpoints, may be used with the latch means of a door with which is used one of the door opening means here involved.

The latch means, therefore, of the automobile door l may be, and preferably is, of the type in which push-buttons or the like are utilized for eiecting the release actuation of said latch means. For example, said latch means may be of the fori'n disclosed in, my copending application for Door opening devices, tiled August 21, 1939, Serial No.'291,240, or in other words, latch means embodying the invention of my prior Patent No. 2,094,413 for Door control mechanism,

, to which patent reference may be had, if desired. However, inasmuch as the latch means of the door l forms no part o f the present invention, no latch meansl for such door is here shown or described.

As will hereinafter more fully appear, each of the three door opening means here illustrated is of simple and inexpensive character and capable of being located between the general planes of the inner and outer side walls of an automobile door and the inner and outer side walls of that portion of the automobile body on which said door'is hinged, there being (see Figs. 2, 5 and three simple and'inexpensive parts capable ofl '7) moreor iess alignment of the outer side wall of such a door and the outer side wall of such a body portion and more or less alignment of the inner side wall of such a door and the inner side p wall of such a body portion, when said door is in its closed position.

As a result, each of said door opening means not only is eminently satisfactory. from structural and' functional standpoints but also, is com mercially practical for a present-day automobile door, as such means is concealed from view when said door is in its closed position and its location, and the extent of its exposure even when said door is in its fully open position, are such as to cause said means to be entirely unobjectionable.

Although door opening means embodying the present invention may take various forms, each of the three door opening means here illustrated comprises a simple and inexpensive self-contained plunger unit which is' carried by either the door structure or its supporting structure, the

' plunger of said unit having cooperative engagement, for door opening and door retaining purposes, with a bearing portion of the other structure, such as the hinge edge wall of such structure 'or a part carried thereby or located in the region thereof. As will hereinafter appear, the bearing portion with which such a plunger has cooperative engagement may be an inclined portion, as in those embodiments bf the invention illustrated in Figs. 1 to 5 inclusive, with the disposition of said inclined bearing portion such that said portion is substantially normal to the path of reciprocation of the plunger when the door is substantially mid-way between its closed position and the predetermined open position to which it is automatically movable; or said bearing portion may be merely a part of the usual or ordinary hinge edge wall of the door or its supporting structure, as -in -that embodiment of the invention illustrated in Fig. 7, in which case, the

disposition of said plunger will be such that itsr path of reciprocation is substantially normal to said bearing portion when said door is substantially mid-way between its closed position and the predetermined open position to which it is automatically movable.

As here shown, the door opening means of Figs. 1 to 4 inclusive has its self-contained plunger unit carried by the automobile body portion 4 so that the inclined bearing portion with which the plunger of said unit has cooperative engagement,

for door opening and door retaining purposes, is'

associated with the automobile doorI I.l As best shown in Fig. 2, said plunger unit is secured to said automobile body portion adjacent its hinge edge wall 3 and between the general planes of its inner and outer side walls 6 and 1, the general plane of each such side wall, as that term is l here used, being the planel which not only includes such side wall but ywhich also extends therebeyond. The inclined bearing portion 9 of the door I is located between the general planes of the inner and outer side walls I and II of said door, and although said inclined bearing necting web portion I1.

being easily and conveniently assembled as a unit, said parts being (a) a bracket, (b) a reciprocable plunger, and (c) expansible means inthe form of a coiled compression spring for constantly urging said plunger rearwardly, for cooperative engagement with the inclined bearing portion. 9 of the door I.

As here shown, the bracket of said lplunger unit comprisesjtwo like members, each being in .the form of a simple sheet metal stamping and each having a semi-cylindrical hollow housing portion I5. an attaching flange portion I6, and a con- In its assembled form, said lbracket has its two housing portions in abutting relationship, its two web portions in like relationship, and its two flange portions in divergingrelationship. said flange portionsl being here screwed or otherwise suitably secured -to the inner side wall 8 of the automobile body portion 4. As clearly shown in Fig. 4, the two housing portions IS of said bracket together form a tubular housing, within which are mounted, as will hereinafter appear, the aforesaid plunger and the coiled compression spring therefor, the front end of said housing being closed and the rear enti thereof being open. As best shown in Fig. 2, the longitudinal axis of said tubular housing is here generally parallel with the side walls 6 and 1 of the automobile body portion 4,' and the open rear end of said housing terminates adjacent the hinge edge wall 3l of said body portion, -there being in such hinge edge wall a suitable opening I8 for the extension therethrough of the reciprocable plunger and for the reception, when the door I is in its closed position, of the door bracket I2 of which the inclined bearing portion 9 is a part. Although the length of said plunger housing may be varied, as desired, the length or forward extent .of the present housing is such that asuitable opening 2li (for the reception of the fron-t end portion of the automobile body bracket of which said housing is a part) is here necessary in the transverse wall 2| of the sheet metal reinforcement pillar 22 with which the automobile body portion `4 is provided.

The plunger of the plunger unit of the door opening means of Figs. 1 to 4 inclusive is here shown as a simple metal tube 23, said tube being slidably mounted in the aforesaid bracket housing and having its front end open and its rear end closed, as best yshown -in Fig. 2. In this embodiment of the present invention, the closed rear end of the plunger tube 23 constitu-tes the head of the plunger, and preferably, therefore, is of convex form in cross-section, as here shown,

or is otherwise suitably shaped for its cooper-v spring 25 of the plunger unit of the door opening `means of Figs. 1 to 4 inclusive is located within the tubular bracket housing 4of such unit,A and l extends into the plunger tube 23 which is slidably mounted in said housing, the front end of said spring beingin engagement with the closed front end of said housing and the rear end of said spring being in engagement with the closed rear end of said plunger tube. As a result of its confinement between the closed ends of said plunger tube and its housing, said spring constantly urges said plunger tube rearwardly from its housing and thus enables the cooperative engagement of the head of said plunger tube with the inclined door bearing portion 9 to automatically effectthe opening o! the door I, as will hereinafter more fully appear.

Although the position to which the door i is' automatically opened by the door opening means of Figs. 1 to 4 inclusive may be varied and predetermined, as desired, the predetermined open position to which said door is here automatically movable4 by said door opening means is a partially open position, namely, the positionof said door in dotted lines, Fig. 2. Further opening movement of said door, such as to its fully open position, can, of course, be manually effected, the fully open position of said door (a position which is not here shown) being determined by the door check (also not shown) with which said doo'r, like all present-day automobile doors, is provided. In order to limit the extent to which the plunger tube 23 may be rearwardly moved by its compression spring 25, during opening movement of the door I, and thereby effectively limit the extent to which said door can be automatically opened, (or in other words, to thereby deu termine the partially open position to which said door is automatically movable), said plunger tube is here provided, adjacent its front end, with a lateral lug 26 which extends at all times into a longitudinally disposed slot 21 of the plunger tube housing, said slot being here formed by registering notches with which the outer longitudinal edges of the two housing portions I5 are provided, as best shown in Fig. 3.

When the door I is in its closed position, the plunger tube 23 engages the inclined door bearing portion 9 adjacent the outer end thereof, as best shown in Fig. 2, and when said door is in the predetermined partially open position to which it is automatically movable by said plunger tube and its compression spring 25, (the dotted line position of said door, Fig. 2), said plunger tube engages said inclined door bearing portion adjacent the inner end thereof, the plunger tube being then in its rearmost position. During thek manual closing of the door I, from the predetermined partially open-position to which it is automatically movable, the plunger tube 23 is moved forwardly (with the consequent compression or loading of its spring 25) by the engagement with said plunger tube of the inclined door bearing portion 9. Therefore, when the door I is in its closed position, the compression spring 25 is fully compressed or loaded, and is thus eiective, upon theunlatching of said door, to automatically move said door to the predetermined partially open position shown in dotted lines, Fig. 2.

In addition to automatically effecting the movement of the door I to a predetermined open position, (a partially open position of said door,

,as here shown), the door opening means of Figs.

1 to 4 inclusive yieldingly resists, through its compression spring 25, the closing of said door from the predetermined open position to which said door is movable. Therefore, as said door has a normal tendency to close (the inclination of its hinge axis x-y being such as to bring that about), said door will remain in the predetermined open position to which it is automatically moved unless said door is manually closed or is manually moved to a further open position if the predetermined position to which said door is automatically movable is a partially open position thereof, as here shown. Inasmuch as the door closing resistance of door opening means embodying the present invention is merely dependent upon the compression resistance, when the door with which such means is used is in the predetermined open position to which it is automatically movable, oi' the compression spring of such means, the door closing resistance of door opening means embodying the present invention may be readily predetermined, as desired, all as will be readily understood.

One oi the important features of the door opening means oi' Figs. l to 4 inclusive is that the inclination of the inclined door bearing portion l, relative to the path of reciprocation of the body plunger cooperable therewith, is such that said bearing portion is substantially normal to the' path of reciprocation of said plunger when the door I is substantially mid-way between its closed position and the predetermined open position (a partially open position, as here shown) to which .said door is automatically movable. This advantageous condition may be expressed another way, namely, by stating that the degree of inclination of said inclined bearing portion, with respect to a line at right angles to the path of-reciprocation of said plunger, whensaid door is' in its closed position, is approximately one-half of the degree to which said door is automatically opened.

'I'his division of the angle of deviation between the closed position of the door I and the predetermined open position to which 4said door is automatically movable is of great importance (especially as said door is a relatively heavy automo bile door, with its hinge axis :r--il so inclined that said door has a normal tendency to close, and inasmuch as the path of reciprocation of the door opening plunger is within one or two inches of said axis), as the resulting material reduction of the bending stresses on said plunger and of the binding effect transmitted to the housing in which it slides enables the door opening means here involved to be -practical for use with such heavy automobile-doors. If, for example, the door I vis automatically opened to 40, the relative angularity of the reciprocable plunger and its cooperating bearing portion is never greater than 20 off of normal, as compared with 40 oif of normal if said bearing portion and the path of plunger reciprocation were normal to each other when said door is closed, as taught by the prior art.

The advantageous relationship of parts here disclosed applies, of course, to any degree to which said door is automatically opened, and by reducing by one half the angle of deviation between the closed position of said door and the predetermined open position to which said door is automatically movable, the efciency of the door opening means here involved is more than doubled, as the vdetrimental ei'fect of this off normal angle progressively increases, all as will be readily understood.

As heretofore pointed out, three forms of door opening means embodying the present invention are here illustrated, one of which, namely, the one shown in Figs. 1 to 4 inclusive, has now been described. Reference will now be made to the other two forms, one of which is shown in Figs. 5 and 6 and the other in Fig. 7, and to avoid needless duplication, only the manner in which they differ from the door opening means of Figs. l to 4 will be .referred to.

In the door opening means of Figs. 1 to 4 inclusive, the plunger unit is carried by the automobile body portion 4 and the inclined bearing portion 9, with which the head of the plunger of said unit cooperates for door opening and door retaining purposes, is carried by the automobile door I, said inclinedbearing portion 9 75 secured to the door hinge edge wall 2 and theA head of said plunger being the closed rear endof the plunger tube 23. In the door opening means of Figs. 5 and 6. the plunger unit is carried by the left front automobile-door la. and the inclined bearing portion 82, with which the head of the plunger of such unit cooperates -for door opening anddoor retaining purposes. is carried by or associated with the automobile b ody portion 4a. As clearly shown in Figs. 5 and 6, the diverging bracket base flanges iBa of the plunger unit of this door opening smeans are welded or otherwise suitably secured to the inner. side wall lila. ofthe door la.' with the disposition of the plunger tube 23 (and hence its path of reciprocation) generally parallel with such door side wall. Although the closed front end-of said plunger tube may engage, for door opening and door retaining purposes, the inclined body lbearing portion 9a,said plunger tube is hereprovided at.its closed front end with a roller l0 or the like for desirable rolling engagement with said inclined body bearing portion. the hinge edge wall 2a of said door being provided with a suitable opening I8a for the extensiontherethrough oi said plunger tube, when said door is open, and for the reception of the plunger tube roller 30, when said door is closed. As here shown, the inclined bearing portion 9a. of said automobile body portion is merely the inner part of a simple and economically iorrnedV depression in the hinge edge wall 3a ,of Vsaid automobile body portion, the inclination of said inclined bearing portion of course. being such that said portion is substantially normal .to the path oi' reciprocation of itscboperating plunger when the door la is substantially mid-way between its closed position and the predetermined partially open position (shown in dotted lines. Fig. 5) to which said door is here automatically movable. l

Inasmuch as the door opening means of Figs. 5 and 6 is otherwise the same as the door opening means of Figs. l to 4 inclusive. and inasmuch as both of said door opening means operate in the same manner, no further reference to the door opening means of Figs. 5 and 6 is believed to be necessary.

In the door opening means of Fig. 7, the selfcontained plunger unit is carri'ed by the automobile body portion lb, on which is hinged; by the use of concealed hinges 5b, a standard left front automobile door Ib. As a result,kthe reciprocable plunger of said unit has cooperative engagement, for door opening and door retaining purposes, with a bearing portion of said door. As here shown, said bearing portion is merelya part (reinforced, if desired, and as here shown) of the hinge edge wall 2b of said door. said hinge edge wall being substantially normal to the inner and .outer side walls ilib and lib of said door, as clearly shown in Fig. -7 in order that the path of reciprocation p-r of the plunger tube 23h will be substantially normal to its cooperating door bearing portion, when said door is substantially mid-waybetween its closed position and the predetermined partially open position (indicated in dotted lines and designated by the reference letter A) to which it is here automatically movable, (or in other words, in the dotted line position indicated by the ,reference It will thus be apparent, therefore, that this door opening means has the advantageous relationship heretofore speciilcally referred to in connection with the door opening means of Figs. l to 4 inclusive.- l

It will also be noted that the diagonal disposition of said plunger tube and its tubular housing locates the path of reciprocation p-r of said plunger tube a suiiicient distance from the hinge axis 32 of the door Ib to provide satisfactory leverage conditions for effecting the automatic opening movement of said relatively heavy door, all as will be readily understood.

Further features and advantages of the invention hereh involved will be readily apparent to those skilled in the art to which it relates.

What I claim is:

l. In combination with a door structure and a supporting structure therefor wherein said door structure is so hinged on said supporting structure that the hinge edge walls of said structures are in oppositely positioned relationship when said door structure is in its closed position, a reciproeable element carried by one of said structures, and expansible means constantly urging said element toward the other structure, said last mentioned structure having an inclined bearing portion in the region of its hinge edge wall and between the general planes of the side walls of such structure for cooperative engagement with said reciproeable element, the force of said expansible means effective upon said inclined bearing portion and acting through said element being suiiicient to automatically bring about the movement oi the door structure, when closed and unlatched, to a predetermined open position. the inclination of said inclined bearing portion being such that said portion is substan- 2. In combination with a door structure and asupporting structure therefor wherein said door structure is so hinged on said supporting structure that the hinge edge walls of said structures are in oppositely positioned relationship when saidv door structure is in its closed position, a reciproeable element carried by one of said structures, and expansible means constantly urging said element toward the other structure, the hinge edge wall of said last mentioned structure having an inclined bearing portion between the general planes of the side walls of such structure for cooperative engagement with said reciprocable element, the force of said expansible means effective upon said inclined bearing portion and acting. through said element being suili-- cient to automatically bring about the movement of the door structure. when closed and unlatched,.to a predetermined open position. the inclination of said/inclined bearing portion being such that saidiortion is substantially normal to the path of reciprocation of said element when said door structure is substantially mid-way between its closed position and the predetermined open position -towhich it is'automatically movable.

3. In combination with a door structure and a supporting structure therefor wherein said door structurels so hinged on said supporting structure that the hinge edge walls of said structures are in oppositely positioned relationship when said door structure is in its closed position, a

reciprocable element carried by one oi' said structures. and expansible means constantly urging said element toward the otherstructure, the path of reciprocation of said element being substantially normal to the general plane of the hinge edge wall of said last mentioned structure when the door structure is in its closed position, said structure toward which said element is urged having an inclined bearing portion in the region of its hinge edge wall for cooperative engagement with said reciprocable element, the force of said expansible means eiective upon said inclined bearing portion and acting through said element being suiilcient to automatically bring about the movement of the door structure, when closed .and unlatched, to a predetermined open position, the inclination of said inclined bearing portion being such that said portion is substantially normal to the path of reciprocation of said element when said door structurev is substantially mid-way between its closed position and the predetermined open position to which it is automatically movable.

4. In combination with a door structure and a supporting structure therefor wherein said door structure is so hinged on said supporting structure that the hinge edge walls: of said structures are in oppositely positioned relationship when said door structure is in its closed position, a reciprocable element carried by one of said structures, and expansible means constantly urging said element toward the other structure, said last mentioned structure having an inclined bearing portion between the general planes of its side walls and in the region of its hinge edge wall but spaced from the general plane toward said reciprocable element of said hinge edge wall for cooperative engagement with said reciprocable element, the force of said expansible means eective upon said inclined bearing portion and acting through said element being suilicient to auto- `nortion is substantially normal to the path of matically movable.

reciprocation of said element when A said door structure is substantially mid-way between its closed position and the predetermined open position to which it is automatically movable.

5. In a device of the character described, a plunger unit comprising a pair of members each having an attaching flange and a semi-cylindrical housing part, the housing parts of said mem bers, when arranged in generally abutting rela tion, forming a cylindrical housing having an open end and a closed end, a hollow plunger having a closed end arranged in said housing and extending through the open end thereof, a compression spring arranged within said housing and extending into said plunger, said spring having engagement with the closed ends of said plunger and said housing and normally urging said plunger from said housing, and means for limiting such movement of said plunger relative to said housing.-

6. In combination with a door structure and a supporting structure therefor wherein said door structure is so hinged on said supporting structure that the hinge edge walls of said structures are in oppositely positioned relationship when said door structure is in its closed position, a reciprocable element carried by one of said structures. and expansible means constantly urging said element toward the other structure, said last 'mentioned structure having a bearing portion in the region of its hinge edge wall and between the general planes of the side walls of such structure for cooperative engagement with said reciprocable element, the force of said expansible means effective upon said bearing portion and acting through said element being sucient to automatically bring about the movement of the door structure, when closed and unlatched, to a predetermined open position, the path of reciprocation of said element being such that it is substantially normal to the aforesaid bearing portion when said door structure is substantially mid-way between its closed position and the predetermined open position to which it is auto- RUDOLPI. scHoNrrzER. 

